Cyclic sulfamidates and sulfonamides are useful building blocks for organic synthesis and drug discovery. Major recent pharmaceutical applications include the carbapenem antibiotic L-786,392 3 and brinzolamide 4 for the treatment of glaucoma (Rosen et al. Science (1999), 283, 703; Dauban et al. Org. Lett. (2000), 2, 2327; Dauban et al. Tetrahedron Lett. (2001), 42, 1037; FIG. 2). Cyclic sulfamidates have also been utilized in the preparation of amino acids (Baldwin et al. Tetrahedron: Asymmetry (1990), 1, 881; Boulton et al. J. Chem. Soc., Perkin Trans. 1 (1999), 1421; Halcomb et al. J. Am. Chem. Soc. (2002), 124, 2534) and have been shown to serve as useful chiral auxiliaries for organic synthesis (Oppolzer et al. Tetrahedron Lett. (1994), 35, 3509; Ahn et al. Tetrahedron Lett. (1998), 39, 6321; Lin et al. Tetrahedron (1999), 55, 13983).
Pioneering work by Breslow and co-workers in 1983 demonstrated catalytic intramolecular amidation of sulfonamides with either transition metal porphyrin complexes or rhodium acetate as catalysts gave cyclic sulfonamides in good yields (Breslow et al. J. Am. Chem. Soc. (1983), 105, 6728). Recent studies by Du Bois and co-workers reported rhodium acetate to be an efficient catalyst for intramolecular amidation of sulfamate esters, affording the corresponding cyclic sulfamidates in good to high yields (Du Bois et al. J. Am. Chem. Soc. (2001), 123, 6935). However, the challenge still remains to seek more stereoselective catalysts for the synthesis of optically active cyclic sulfamidates. To our knowledge, the asymmetric intramolecular amidation of such substrates using chiral catalysts is not known.
Metalloporphyrin catalyzed intermolecular nitrogen-atom transfer has attracted considerable attention because of their unique relationship to heme-containing enzymes, high stereoselectivity and catalytic turnover (Che et al. Org. Lett. (2000), 2, 2233). Moderate ee values have been obtained for asymmetric aziridination of alkenes and amidation of saturated C—H bonds (Che et al. Chem. Commun. (1997), 2373; Che et al. Chem. Commun. (1999), 2377; Marchon et al. Chem. Commun. (1999), 989; Che et al. Chem. Eur. J. (2002), 1563). The successful isolation of bis(tosylimido)ruthenium(VI) porphyrins have provided useful insights into the mechanism of ruthenium porphyrin catalyzed intramolecular nitrogen-atom transfer reactions (Che et al. J. Am. Chem. Soc. (1999), 121, 9120; Che et al. Chem. Eur. J. (2002), 1563).
The present invention describes the first intramolecular amidation of sulfamates catalyzed by a metalloporphyrin and asymmetric intramolecular amidation of sulfamidates catalyzed by a transition metal complex supported by a porphyrin macrocycle. The target cyclic sulfamidates can be easily converted to α- or β-amino alcohols (Du Bois et al. J. Am. Chem. Soc. (2001), 123, 6935), which are important precursors for drug synthesis and for the synthesis of chiral ligands for asymmetric catalysis (Kajiro et al. Synlett (1998), 51; Davies et al. Tetrahedron Lett. (1996), 37, 813; Ghosh et al. J. Am. Chem. Soc. (1996), 118, 2527).